Electrodeposition of nickel



United States Patent 3,366,557 ELECTRODEPOSITION 0F NICKEL DonaldGardner Foulke, Watchung, Otto Kardos, Red

Bank, and Herman Koretzky, Belleville, N.J., assignors to Hanson-VanWinkle-Muuning Company, a corporation of New Jersey No Drawing. FiledJuly 22, 1958, Ser. No. 750,258 8 Claims. (Cl. 20449) This inventionrelates to electroplating and, more particularly, to electrodepositingnickel from an aqueous nickel-plating bath. The invention is based onthe discovery that water-soluble reaction products prepared bybasecatalyzed additions of various alkynols to epoxides are remarkablyeffective for promoting the formation of bright and ductile nickelelectrodeposits over a Wide current density range when incorporated in anickel electroplating bath, particularly in conjunction with varioussulfooxygen compounds.

The electrodeposition of nickel from a plating bath containing asulfo-oxygen carrier brightener additive generally produces asemi-bright deposit at the cathode, particularly at the lower currentdensities. Increasing the current density fiequently decreases theoverall brightness of the deposit and often induces the formation ofhaze, especially at the low and middle current density ranges. \Vhen,however, a small quantity of an alkynolepoxide adduct, prepared via abase-catalyzed addition of hydroxy-substituted acetylenic compound to anepoxide, is incorporated in the plating bath together with a sulfooxygencompound, the brightness capacity of the bath is extended, and theelectrodeposit is ductile and bright over a wide current density range.

Because almost any hydroxy-substituted acetylenic compound can be madeto react in the presence of a base with an epoxide, absent sterichindrance either of the hydroxy group or of the oxirane ring, no singlecommon structural feature can be advanced to unequivocally characterizeall of the reaction products which are prepared by a baseinducedreaction between an alkynol and an epoxide and which may be used in anickel-plating bath in accordance with the invention. Structuralcharacterizations of several of these reaction products, which have beenused successfully in nickel-plating baths, have been made on the basisof structural similarities between the alkynols used to prepare thesereaction products. For example, where the reaction product is preparedby a base-induced addition of an a-hydroxy aceylenic compound to anepoxide, then the common structural feature of all such adducts is thepresence of a fi-oxyethoxy group on the carbon atom vicinal to theacetylenic bond, as represented by the following structural formula:

Where the reaction product is prepared from an alkynol in which one ormore hydroxy groups are several carbons removed from the acetylenicbond, then this B-oxyethoxy grouping will be correspondingly removedfrom the acetylenic bond.

Only relatively small quantities of the alkynol-epoxide reactionproducts are required in the plating bath, especially when they are usedin conjunction with a sulfooxygen carrier brightener, for the presencein the molecule of both an acetylenic bond and a fl-oxyethoxy groupingappears to exert a pronounced synergistic effect on the brighteningcapacity of the sulfo-oxygen compound. In general, concentrations of thealkynol-epoxide reaction products as low as 0.1 millimole per liter areeffective, but in many cases at least 1 millimole per liter should beemployed to secure the full benefit of their presence in the bath. Thereappears to be no critical upper limit on the concentration of thesealkynol-epoxide adducts save solubility, but there is no advantagegenerally in employmononuclear aryl, alkyl, alkenyl, alkoxy, alkenoxy,and

ing more than 250 millimoles per liter, and in most plating bathssubstantially the full benefit of its presence is achieved with 100millimoles per liter or less.

Any alkynol-epoxide reaction product prepared via a base-inducedreaction between a hydroxy-substituted acetylenic compound and anepoxide and which is capable of being dissolved in an aqueous solutionof either acid or base and does not undergo decomposition uponprotonation or in the presence of a nucleophile may be selected forinclusion in the plating solution. Particularly satisfactory resultshave been obtained by using additives (reaction products) prepared fromu-hydroxy-substituted acetylenic compounds, the only limitations beingthat the a-hydroxy acetylenic compound used to prepare the additivecontain at least one hydroxy group on a carbon atom vicinal to theacetylenic bond and that this hydroxy group be sufiiciently unhinderedto' form an alkoxide ion and react with an oxirane ring. If these twoconditions are met, then any a-hydroxy acetylenic compound, includingthose which are polyols, polyacetylenic, or both, or even contain otherfunctional groups, may be used to form an adduct which is suitable forinclusion in a nickel-plating bath.

A preferred process according to this invention for producing brightnickel deposits comprises electrodepositing nickel from an aqueoussolution of at least one nickel salt in which there is dissolved fromabout 0.1 to about 250 millimoles per liter of a water-soluble reactionproduct of a base-catalyzed addition of an m-hydroxy acetylenic compoundwith from N to xN times an equivalent weight of an epoxide, where N isan integer from 1 to 20 and x is equal to the number of hydroxy groupsper molecule of the acetylenic compound. The epoxides used in preparingthis reaction product are structurally represented by the formula inwhich each of R and R are substituents of the group substituted, andepoxy-substituted alkyl and alkenyl groups,

and each of R and R are substituents of the group consisting ofhydrogen, chloromethyl, carboxy, cyano,

hydroxy-substituted, alkoxy-substituted, alkenoxy-substituted, andepoxy-substituted alkyl, alkenyl, alkoxy, and alkenoxy groups. To obtainalkeynol-epoxide reaction products which are readily soluble in aqueoussolution, the

chain length of each of the oxirane substituents (R R R and R of theparticular epoxide used to prepare the reaction product preferablyshould contain not more than from 5 to 7 carbon atoms. However, if theseoxirane substituents contain a sufiicient number of hydrophilic groups,then the number of carbon atoms in the oxirane substituents does notmaterially affect the water solubility of the resultant alkynol-epoxidereaction product.

The effect of these alkynol-epoxide reaction products on the brighteningcapacity of various sulfo-oxygen compounds is especially pronounced whenthey are used in the nickel plating solution together with from A; tograms per liter of a water-soluble sulfo-oxygen compound of the groupconsisting of unsaturated aliphatic sulfonic acids, mononuclear andbinuclear aromatic sulfonic acids, heterocyclic sulfonic acids,mononuclear sulfinic acids, the alkali metal, ammonium, magnesium, andnickel salts of these acids, and mononuclear aromatic sulfonamides andsulfonimides.

Preparation of the alkynol-epoxide reaction products is generallyaccomplished by inverse addition of the epoxide to a reaction mixture ofthe alkynol and a catalytic amount 'of base. Inverse addition of theepoxide to the alkynol, rather than the converse, is the most frequentlyused technique since it afiords close control over the number ofrecurring polyoxy groups in the end-product. Other reaction techniqueshave been used to prepare the alkynolepoxide adducts, includingsimultaneous addition of both reactants to a solution of base or initialpolymerization of the epoxide followed by reaction with the alkynol, butin general they are difficult to control and do not yield uniformproducts.

Although the reaction between an alkynol and an epoxide is convenientlytermed an addition, and although the term adducts is used.interchangeably in the specification with reaction products, since noelimination (or condensation) of water occurs during the reaction and ina sense the end-product is the additive of the reactant moieties, thereaction is properly classified as a nucleophilic aliphatic substitutionwhich proceeds via the forma tion of an acetylenic alkoxide anion whichattacks one of the epoxide carbons and causes nucleophilic fission ofthe oxirane ring. Because the reaction is a nucleophilic aliphaticsubstitution, and is generally of second-order kinetics (5 2), certaingeneralizations can be made which will enable prediction of thestructure of the reaction products. For example, the acetylenic alkoxideanion preferentially attacks the primary epoxide carbon, if one ispresent, in a higher epoxide rather than secondary or tertiary carbon.Where both epoxide carbons are secondary or tertiary, then absent sterichindrance the anion will attack that epoxide carbon which possesses thehighest fractional positive charge (6 as shown by the following reactionsequence:

, Virtually any basic catalyst may be used in preparing thesealkynol-epoxide reaction products, selection of a suitable catalystbeing dependent upon the particular alkynol used in the reaction. Wherea-hydroxy acetylenic compounds are used to prepare the additives, thenthe basicity of the catalyst becomes important, since under certainconditions the anion of an a-hydroxy acetylenic compound is capable ofundergoing a reverse-Favorskii reaction or cleavage into an acetylideion and a carbonyl, as illustrated by the following reaction:

Azan a B 050 o=o This side reaction may be prevented by employing mildreaction conditions when a strongly basic catalyst is employed, or byusing a mild base, such as triethylamine, when more vigorous reactionconditions are necessary to complete the reaction.

The alkynol-epoxide reaction products prepared from a-hydroxy acetyleniccompounds have been found to be unusually effective brightening agents,especially when used in a plating bath in conjunction with varioussulfobeen obtained using reaction products (alkynol-epoxide adducts)prepared from a-hydroxy acetylenic compounds having a structurerepresented by the formula in which each of R and R are substituents ofthe group consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroXy-substituted, alkoXy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and R is a substituent of the groupconsisting of hydrogen, halogen, alkyl, alkenyl, hydroxy-substituted,alkoxy-substituted, and amino-substituted alkenyl and alkynyl groups,and substituted-alkyl groups having the structural configuration inwhich each of R and R are substituents of the group consisting ofhydrogen, alkyl, alkenyl, alkynyl, and bydroXy-substituted,alkoxy-substituted, and amino-substituted alkyl, alkenyl, and alkynylgroups, and R is a substituent of the group consisting of hydroxy,alkoxy, formoxy, alkanoxy, and halogen. Where R is a substituted-alkylgroup having the above structural configuration, in which R is a hydroxygroup, then the alkynol is termed an a,a'-dihydroxy acetylenic compound,since both carbon atoms vicinal to the same acetylenic bond contain freehydroxy groups. The compounds listed in Table I are examples of variousa-hydroxy acetylenic compounds from which effective brightening agentsmay be prepared.

TABLE L-a-HYDROXY ACETYLENIC COMPOUNDS R C C(|JOH Table II sets forthexamples of a,a'-dihydroxy acetylenic compounds which may be used toprepare the alkynol-epoxide reaction products which, in turn, may beoxygen compounds. Particularly satisfactory results have employedsuccessfully in embodiments of this invention.

TABLE II.a,a-DIHYDROXY ACETYLENIC COMPOUNDS 2,5-diphenyl-3-hexyne-2,5dio1 CsHs C C a Ct s 1 ,1,4,4-tetraphenyl-2-butyne-1,4-diol CeHs CtHsCeHs C n s The epoxides used in preparing the alkynol-epoxide reactionproducts are structurally characterized by the formula Rh RB in whichR,,, R R and R are the substituents hereinbefore specified. Uponreaction with the alkynol and nucleophilic fission of the oxirane ring,the epoxide moiety is transformed in the reaction product into a chainof recurring ,B-oxyethoxy groupings, the number of such groupings in themolecule being dependent upon the proportions of alkynol and epoxideemployed in the reaction. As a general rule, the most satisfactorybrightening agents are those which are prepared by reacting the alkynolwith from N to xN times an equivalent weight of epoxide, where N is aninteger from 1 to 20 and x is equal to the number of free hydroxy groupsin the alkynol molecule. Table III sets forth examples of the epoxideswhich have been reacted with various alkynols, including those listed inTables I and II, to form additives which may be used successfully inembodiments of this invention.

TABLE IIL-EPOXIDE S TABLE IV.ORGANIC SULFO-OXYGEN COMPOUNDS (l)Unsaturated aliphatic sulfonic acids, and alkali metal, ammonium,magnesium, and nickel salts thereof:

Sodium vinyl sulfonate, H C CHSO Na Sodium allyl sulfonate, H C=CHCH SONa (2)Mononuclear aromatic sulfonic acids, and alkali metal, ammonium,magnesium, and nickel salts thereof:

Benzene monosulfonic acid, C H SO H Sodium benzene monosulfonate, C H SONa Nickel benzene monosulfonate, (C I-i SO Ni Sodium p-toluenemonosulfonate, CH C H SO Na p-Chlorobenzene sulfonic acid, ClC H SO HR,,\ /O\ /Ra R e Compound Ra Rb R 1: Rd

Ethylene oxide -H H -H H Propylene oxide H H H CH; Epichlorohydrin H H-H --CH2C1 Butadiene monoxide H H C2Hs H Butadieue dioxide H -H C2H O HAllyl glyeidyl ether -H H -CHz(C3H O) H Isopropyl glycidyl ether H HC3H1 H 2,3-epoxybutaue-.. CHa H H -CH3 Styrene oxide H -H H C6H5Di-(1,2-dimethyl-1,2-epoxypropyl) ether CH3 CH3 -CH (C5HQO)O1,2-epoxypentane H H H -C3H7 a,,6Epoxypropionic acid -H H H COOH01,5-EPOXYP10 pionitrile H H I-I --CN Among the most satisfactorybrightening agents are those prepared by reacting either an rx-hydroxyor an a,a'-dihydroxy acetylenic compound, such as those listed in TablesI and II, with either ethylene oxide or epichlorohydrin. These adductsreadily dissolve in both acidic and basic nickel-plating baths, and areunusually effective in such baths both in promoting the formation ofbright and ductile electrodeposits over wide current density ranges andin extending the brightening range of sulfooxygen carrier brighteneradditives. Two such adducts which are notably effective are the u,t'-di-(polyoxy)-2- butynes obtained upon the reaction of2-butyne-l,4-diol with ethylene oxide and with epichlorohydrin.

2-butyne-l,4-diol reacts with ethylene oxide in the presence of a baseto form a l,4-di-(hydroxypolyethoxy)-2- butyne which is structurallycharacterized by the formula and with epichlorohydrin to form a1,4-di-[hydroxypoly (fi-chloromethylethoxy) ]-2-butyne, the structure ofwhich is represented by the formula n in both formulas being an integerfrom 1 to 20. The

brightening efiect of both of these reaction products in combinationwith various sulfo-oxygen compounds in nickel plating baths isespecially pronounced.

Sodium p-chlorobenzene sulfonate, ClC H SO Na Sodium p-bromobenzenesulfonate, BrC H SO Na 1,2-dichlorobenzene sulfonic acid, Cl C H SO I-I1,2- or 2,5-dich1orobenzene sulfonate sodium salt,

Cl C H SO Na Sodium m-benzene disulfonate, C H (SO Na) m-Benzenedisulfonic acid, C H (SO H) Nickel m-benzene disulfonate, C H4(SO Nio-Sulfobenzoic acid monoammonium salt,

1-amino-2,5-benzene disulfonic acid, H NC H (SO H) o-Aminobenzenesulfonic acid, H NC H SO H (3) Mononuclear aromatic sulfonic acids, andalkali metal, ammonium, magnesium, and nickel salts thereof:

Sodium benzene sulfinate, C H SO Na Sodium p-toluene sulfinate, CH C HSO Na Binuclear aromatic sulfonic acids, and alkali metal, ammonium,magnesium, and nickel salts thereof:

Z-naphthalene monosulfonic acid, C H SO H 1,5- or 2,7-naphthalenedisulfonic acid, C H (SO H) Nickel 1,5- or 2,7-naphthalene disulfonate,C H (SO Ni Sodium naphthalene trisulfonate, C H (SO Na) 3 Naphthalenetrisulfonic acid, C H (SO H) 3 Diphenyl p,p'-disulfonic acid, HSO C H CH SO H 2-naphthol-3,6-disulfonic acid, HOC H (SO H) Sodium2-naphthol-3,6-disulfonate, HOC H (SO Na)1-naphthylamine-3,6,S-trisulfonic acid, a 1Q 4( B )3 (6) Heterocyclicsulfonic acids, and alkali metal, ammonium, magnesium, and nickel saltsthereof:

Thiophene sulfonic acid, C H S-SO H Sodium thiophene sulfonate, C H S-SONa 2- (4-pyridyl)ethyl sulfonic acid, C H N C H SO H For the most part,only the free sulfonic acids are listed in Table IV. However, the alkalimetal, ammonium, magnesium, and nickel salts of these acids are in allcases the full equivalent of the corresponding sulfonic acid, and may beused in its place in carrying out the process of the invention.

Table V summarizes the preparation of the reaction products of fourdifferent epoxides with 2-butyne-l,4-diol which were employed incarrying out the examples of the invention that are set forth below.Each of the compounds listed in Table V was prepared by reacting 1.0mole of 2-butyne-1,4-diol with 2.0 moles of the epoxide in the presenceof from 0.5 to 5 percent by weight of a basic catalyst. The basicity ofthe catalyst as well as the reaction conditions employed weresufficiently mild so that the danger of a reverse-Favorskii reaction(which would have resulted in the cleavage of 2-butyne-1,4-di0l toacetylene and formaldehyde) was precluded. A fifth compound, 1,4-di(B,'y-epoxypropoxy)-2-butyne, was prepared by dehydrohalogenating analiquot portion of 1,4-di-(B- hydroxy-y-chloropropoxy)-2-butyne, whichwas initially prepared by reacting epichlorohydrin with 2-butyne-1,4-diol.

av'ternperature of C. Mild agitation of the bath'was provided in eachcase. As indicated in Table VI, each of the epoxide adducts was employedin a solution free from a sulfo-oxygen compound, and again in a solutionin which 15 grams per liter of sodium naphthalene-1,3,6-trisulfonate hadbeen dissolved.

TABLE VI.BRIGHT NICKEL PLATING WITH 1,4-DI (POLY- OXY)2-BUTYNES 1Reaction product of 2-butyne-l,4diol and two equivalents of butadienemonoxide; also contains 1,4-di(a-hydroxymethyl-B-propenoxy) 2 butyne aswell as l-(fl-hydroxy-y-butenoxy)-4-(u-hydroxymethyl-Bpropenoxy)-2-butyne.

2 Reaction product of 2-butyne-1,4-diol and two equivalents of allylglycidyl ether; also contains1,4-di-(1-hydroxymethyl-3-oxa-5-hexen0xy)-2-butyne as well as1-(1'-hydroxymethyl-3-oxa-5-hexenoxy)-4-(2-hydroxy-4oxa-6-heptenoxy)-2-butyne.

Although Table VI indicates that bright deposits are obtained when theepoxide adducts of alkynols are used alone (without the sulfo-oxygencompound), the current density range of maximum brightness in such casesis somewhat restricted. By way of contrast, when the electrodeposit wasreceived on the test panel under identical plating conditions, but usinga plating bath containing only the sulfo-oxygen compound, the depositwas semibright over a wide current density range and possessed a stronghaze at the middle and low current density ranges. For optimum results,therefore, the plating bath should contain both the sulfo-oxygencompound and the epoxidealkynol reaction product.

The efiectiveness of various sulfo-oxygen compounds in providing a widecurrent density range over which bright TABLE V.-PREPARATION OF1,4-DI-(POLYOXY)-2-B UTYNES ZblllZYIlE-lfl dlOl (1.0) Allyl glycidylether (2.0).- K2003 (0.5%)

Reactants Products Acetylemc Compound Epoxide (moles) Catalyst (moles)(percent) Z-butyneJA-diol (1.0) Ethylene oxide (2.0) NaOH (5%)1,4-di-(5-hydroxyethoxy)2-butyne. 2-butyne-l,4-d10l (1.0)Eprchlorohydrin (2.0)"-.. N azCOQ (5%)1,4-di-(B-hydroxychl0ropropoxy)-2-butync.

(a) 1,4-di-(/3-hydroxy-' butenoxy)-2-butyne (predominant product).

Z-butyne-lA-drol (1.0)-.-- Butadiene monoxide (2.0). NaOH (3%) (b)1,4-di-(a-hydroxyrnethyl-B-propenoxy)-2-butyne.

propenoxy)-2-butyne.

hydroxy-apxa-d-heptenoxy)-2-butyne.

Table VI sets forth the results obtained when nickel waselectrodeposited from the standard Watts plating bath which alsocontained one of the five epoxide adducts described in Table V. The pHof the bath was adjusted to about 3.4 in each case, and theelectrodeposit formed at of 65 C.

deposits can be produced from a bath containing 1,4-di-(fi-hydroxyethoxy)-2-butyne is illustrated by the examples set forth inTableVII below. Electroplates of nickel, deposited from a highlypurified Watts plating bath (pH=3.4) containing 300 grams per liter ofnickel sulfate (NiSO -7H O), 45 grams per liter of nickel chloride (NiCl-6H O), 41.25 grams per liter of boric acid (H BO3), and 0.4 gram perliter of 1,4-di-(fi-hydroxyethoxy)-2-butyne, increased in brilliancewhen a sulfooxygen compound was used in conjunction with theepoxide-alkynol adduct. Plating operations were carried out using mildair agitation and at a bath temperature TABLE VII.EFFECT OF1,4-DI-(fl-HYDROXYE'IHOXY)-2- BUTYNE AND VARIOUS SULFO-OXYGEN COMPOUNDSON BRIGHT NICKEL PLATING 1,4-di-(B-hy- Current Densi- SulioOxygenCompound Cone. droxyethoxy)- ty Range (a.s.f.)

(gun/l.) 2-hutyne of maximum (gm./l.) brightness Sodiumvinylsulicnate 1. 1 0. 4 1 to 40. p-Toluenesulfonamide 0. 4 0. 4 1 to80. Sodium benzene l,3-disul- 3. 2 0. 4 1 to 80. fonate. 17. 6 0. 4 1 to80. o-Sulfobenzoic imide O. 0. 4 1 to 80.

a Reaction product or Zhutyne-lA-diol and two equivalents of ethyleneoxide; may contain small quantities of polymeric condensates.

The general principle illustrated in Table VlI, that the plating rangeof a bath containing an epoxide-alkynol adduct may be extended by theaddition to that bath of a sulfo-oxygen compound, was repeatedly andconsistently verified in another series of tests using a large number ofepoxide-alkynol adducts and of sulfa-oxygen brightening addition agents.

In the foregoing examples of the invention, the reaction products of abase-catalyzed reaction of an ahydroxy acetylenic compound with anepoxide were used successfully in the standard Watts nickelelectroplating bath, which is prepared by dissolving nickel sulfate,nickel chloride, and boric acid in water. Similar advantages are alsoattained when the epoXide-alkynol adducts are dissolved in other typesof aqueous acidic or basic nickel electroplating baths. For example, theepoxidealkynol adducts are beneficial when used in straight nickelsulfate baths, in straight nickel chloride baths, and in various othernickel plating baths based on using nickel formate, nickel sulfamate, ornickel fiuoborate as the nickel salt which is dissolved in an aqueousacidic solvent. In other tests, bright to brilliant nickel electroplateswere obtained from aqueous alkaline nickel plating baths containing theepoxide-alkynol adduct. Consequently, the invention is applicable toelectrodeposition from any aqueous solution of one or more nickel salts.

We claim:

1. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved frorn about 0.1 to about 250 millimolesper liter of an u,a'-di(polyoxy) acetylenic compound having a structurerepresented by the formula in which each of R and R are substituents ofthe group consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroxy-substituted, alkoXy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, each of R and R are substituents of thegroup consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroxy-substituted, alkoXy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and n is an integer from 1 to 20.

2. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about A to about 80 grams perliter of a water-soluble sulfo-oxygen compound of the group consistingof unsaturated aliphatic sulfonic acids, mononuclear and binucleararomatic sulfonic acids, heterocyclic sulfonic acids, mononucleararomatic sulfinic acids, the alkali metal, ammonium, magnesium, andnickel salts of said acids, and mononuclear aromatic sulfonamides andsulfonirnides, and from about 0.1 to about 250 milli- 10 moles per literof an a,u-di(polyoxy) acetylenic compound having a structure representedby the formula in which each of R and R are substituents of the groupconsisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroxy-substituted, alkoXy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, each of R and R are substituents of thegroup consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroxy-substituted, alkoxy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and n is an integer from 1 to 20.

3. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about A to about grams per liter01 a water-soluble sulfo-0xygen compound of the group consisting ofunsaturated aliphatic sulfonic acids, mononuclear and binuclear aromaticsulfonic acids, heterocyclic sulfonic acids, mononuclear aromaticsulfinic acids, the alkali metal, ammonium, magnesium, and nickel saltsof said acids, and mononuclear aromatic sulfonamides and sulfonimides,and from about 1 to about millimoles per liter of a water-solublereaction product of a basecatalyzed reaction of an a,a'-dihydIOXyacetylenic compound with from N to xN times an equivalent weight of anepoxide, Where N is an integer from 1 to 20 and x is equal to the numberof hydroxy groups per molecule of the a,a'-dihydroxy acetylenic compoundwhereby both on and a hydroxy groups are converted into ether radicals,said a,a'-dihydroxy acetylenic compound having a structure representedby the formula in which each of R and R are substituents of the groupconsisting of hydrogen, alkyl, alken i, alkynyl, andhydroxy-substituted, alkoxy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and each of R and R are substituents of thegroup consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroXy-substituted, alkoxy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and said epoxide having a structurerepresented by the formula in which each of R and R are substituents ofthe group consisting of hydrogen, alkyl, alkenyl, mononuclear aryl andaralkyl groups, and hydroxy-su-bstituted, alkoxy-snbstituted, andepoxy-substituted alkyl and alkenyl groups, and each of R and R aresubstituents 0f the group consisting of hydrogen, chlorornethyl,carboXy, cyano, mononuclear aryl, alkyl, alkenyl, alkoxy, alkenoxy, andhydroXy-su'bstituted, alkoXy-substituted, alkenoXy-substituted, andepoxy-substituted alkyl, alkenyl, alkoxy, and alkenoxy groups.

4. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about A to about 80 grams perliter of a water-soluble sulfo-oxygen compound of the group consistingof unsaturated aliphatic sulfonic acids, mono-nuclear and binucleararomatic sulfonic acids, heterocyclic sulfonic acids, mononucleararomatic sulfinic acids, the alkali metal, ammonium, magnesium, andnickel salts of said acids, and mononuclear aromatic sulfonamides andsulfonimides, and from about 1 to about 100 millimoles per liter of anc,a'-di(polyoxy) acetylenic compound having a structure represented bythe formula in which each of R and R are substituents of the groupconsisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroxy-substituted, alkoxy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, each of R and R are substituents of thegroup consisting of hydrogen, alkyl, alkenyl, alkynyl, andhydroXy-substituted, aikoxy-substituted, and amino-substituted alkyl,alkenyl, and alkynyl groups, and n is an integer from 1 to 20.

5. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about /4 to about 80 grams perliter of a water-soluble suito-oxygen compound of the group consistingof unsaturated aliphatic sulfonic acids, mono-nuclear and binucleararomatic sulfonic acids, heterocyclic sulfonic acids, mononucleararomatic sulfinic acids, the alkali metal, ammonium, magnesium, andnickel salts of said acids, and mononuclear aromatic sulfonamides andsulfonimides, and from about 1 to about 100 millimoles per liter of awater-soluble reaction product of a basecatalyzed condensation of2-butyne-l,4-diol with from N to 2N times an equivalent weight of anepoxide whereby both hydroxy groups of said 2-butyne-l,4-diol areconverted into ether radicals, said epoXide having a structurerepresented by the formula in which each of R and R are substituents ofthe group consisting of hydrogen, alkyl, alkenyl, mononuclear aryl andaralkyl groups, and hydroxy-substituted alkoxysubstituted, andepoxy-substituted alkyl and alkenyl groups, and each of R and R aresubstituents of the group consisting of hydrogen, chloromethyl, carboxy,cyano, mono-nuclear aryl, alkyl, alkenyl, alkoxy, alkenoxy, andhydroxy-substituted, alkoxy-substituted, alkenoxy-substituted, andepoxy-substituted alkyl, alkenyl, alkoxy, and alkenoxy groups, and whereN is an integer from 1 to 20.

6. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about A to about 86 grams perliter of a water-soluble sulfo-oxygen compound of the group consistingof unsaturated aliphatic sulfonic acids, mononuclear and binucleararomatic sulfonic acids, heterocyclic sulfonic acids, mononucleararomatic sulfinic acids, the alkali metal, ammonium, magnesium, andnickel salts of said acids, and mononuclear aromatic sulfonamides andsulfonimides, and from about 1 to about 100 millimoles 12 a per liter ofa Wat r-soluole a,a'-di(polyoxy)-2-hutyne having a structure representedby the formula in which n is an integer from 1 to 20.

7. The process'for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt in which there is dissolved from about A to about grams per literof a water-soluble sulfo-oxygen compound of the group consisting ofunsaturated aliphatic sulfonic acids, mononuclear and binuclear aromaticsulfonic acids, heterocyclic sulfonic acids, mononuclear aromaticsulfinic acids, the alkali metal, ammonium, magnesium, and nickel saltsof said acids, and mononuclear aromatic sulfonarnides and sulronimides,and from about 1 to about millimoles per liter of a water-solublea,a-di(polyoxy)-2-butyne having a structure represented by the formulaCH2C1 01-1201 H[OCHCH2]uOOH2CH2 OECCH2O[GH2CHO]n H in which n is aninteger from 1 to 20.

8. The process for producing bright nickel deposits which compriseselectrodepositing nickel from an aqueous solution of at least one nickelsalt characterized in that there is dissolved in the nickel plating bathat least about 1 millimole per liter of a compound of the formula R OCH-CEC-CH O-R wherein R is a radical selected from the group consisting ofOH CH -11, CH2-( 3HCEzC1,-C2H40H and CHz( 3HOH and R is a radicalselected from the group consisting of on CH3 and sodium allyl sulfonatein an amount of at least about 0.3 gram/liter.

References Cited UNITED STATES PATENTS 3,305,462 2/1967 OstroW et a1.2O449 2,849,353 8/1958 Kardos 204-49 2,882,208 4/1959 Becking et a1.2O4-49 2,686,757 8/1954 Cook et a1. 294-49 2,712,522 7/1955 Kardos eta1. 20449 2,784,152 3/1957 Ellis 20449 7 FOREIGN PATENTS 542,292 11/1955Belgium. 924,490 3/1955 Germany.

HOWARD S. WILLIAMS, Primary Examiner.

JOHN R. SPECK, Examiner. G. KAFLAN, M. 'r. TI LLMAN, AssistantExaminers.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,366,557 January 30, 1968 Donald Gardner Foulke et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 6, line 59, for "sulfonic" read sulfinic column 11, lines 3 to 6,for that portion of the formula reading R R I 4 4 read 13' R 5 Signedand sealed this 1st day of April 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissionerof Patents

3. THE PROCESS FOR PRODUCING BRIGHT NICKEL DEPOSITS WHICH COMPRISESELECTRODEPOSITING NICKEL FROM AN AQUEOUS SOLUTION OF AT LEAST ONE NICKELSALT IN WHICH THERE IS DISSOLVED FROM ABOUT 1/4 TO ABOUT 80 GRAMS PERLITER OF A WATER-SOLUBLE SULFO-OXYGEN COMPOUND OF THE GROUP CONSISTINGOF UNSATURATED ALIPHATIC SULFONIC ACIDS, MONONUCLEAR AND BINUCLEARAROMATIC SULFONIC ACIDS, HETEROCYCLIC SULFONIC ACIDS, MONONUCLEARAROMATIC SULFINIC ACIDS, THE ALKALI METAL, AMMONIUM, MAGNESIUM, ANDNICKEL SALTS OF SAID ACIDS, AND MONONUCLEAR AROMATIC SULFONAMIDES ANDSULFONIMIDES, AND FROM ABOUT 1 TO ABOUT 100 MILLIMOLES PER LITER OF AWATER-SOLUBLE REACTION PRODUCT OF A BASECATALYZED REACTION OF ANA,A''-DIHYDROXY ACETYLENIC COMPOUND WITH FROM N TO XN TIMES ANEQUIVALENT WEIGHT OF AN EPOXIDE, WHERE N IS AN INTEGER FROM 1 TO 20 ANDX IS EQUAL TO THE NUMBER OF HYDROXY GROUPS PER MOLECULE OF THEA,A''-DIHYDROXY ACETYLENIC COMPOUND WHEREBY BOTH A AND A'' HYDROXYGROUPS ARE CONVERTED INTO ETHER RADICALS, SAID A,A''-DIHYDROXYACETYLENIC COMPOUND HAVING A STRUCTURE REPRESENTED BY THE FORMULA
 8. THEPROCESS FOR PRODUCING BRIGHT NICKEL DEPOSITS WHICH COMPRISESELECTRODEPOSITING NICKEL FROM AN AQUEOUS SOLUTION OF AT LEAST ONE NICKELSALT CHARACTERIZED IN THAT THERE IS DISSOLVED IN THE NICKEL PLATING BATHAT LEAST ABOUT 1 MILLIMOLE PER LITER OF A COMPOUND OF THE FORMULA